Some are down over the previous 6 months, but not by 50%. At least among the largest.

    Company:     6 month change:
    ============================
    Palantir:    +20%
    Salesforce:  -9%
    Shopify:     +40%
    Intuit:      -26%
    ServiceNow:  -30%
    Adobe:       -17%
    CrowdStrike: -1.5%
    Snowflake:   -3%
    Cloudflare:  0%
    Autodesk:    -9%

https://www.mikesonders.com/largest-saas-companies/